Self-running robot having pressing sensing function and control method thereof

ABSTRACT

Disclosed is a pressing sensing technology of a self-running robot, comprising a pressing sensing unit for sensing pressing on the top of the self-running robot and a microprocessor for controlling driving of the self-running robot in accordance with the sensing signal from the pressing sensing unit to enable the self-running robot to escape from an area where the pressing has occurred. Accordingly, the invention has an advantage in that it can prevent a function degradation and damage of the self-running robot by changing a running direction of the self-running robot when pressing on the self-running robot is sensed to enable the self-running robot to escape from the area where the pressing has occurred, or notifying, when the pressing cannot be released, a user of the state in voice to take any necessary action.

BACKGROUND OF THE INVENTION

This U.S. non-provisional patent application claims priority under 35U.S.C. § 119 of Korean Patent Application 2005-34144 filed on Apr. 25,2005, the entire contents of which are hereby incorporated by reference.

1. Field of the Invention

The present invention relates to a self-running robot, and moreparticularly, to a pressing sensing technology of a self-running robotto sense pressing on the top of the self-running robot, and controldriving of the self-running robot based on the sensed result so as toavoid obstacles or notify a user of the sensed result.

2. Description of Related Art

Robots were developed for industrial purposes and used as a part of afactory automation system. Further, the robots have been utilized tocollect or gather information on behalf of humans in extremeenvironments humans cannot endure. Such a robot engineering field, whilebeing recently used in a newest space development industry, has beencontinuously developed, and human-friendly home robots have beendeveloped in recent years. A typical example of such human-friendly homerobots is a cleaning robot.

The cleaning robot that is of a self-running type is an appliance whichsucks dirt or debris, while self-running in a predetermined cleaningarea such as a house or an office. Such a cleaning robot includes amoving unit including left and right wheel motors for moving thecleaning robot, a plurality of sensors for sensing obstacles so as toprevent the cleaning robot from striking obstacles in the cleaning area,and a microprocessor for controlling the overall device of the cleaningrobot, together with constructions of a general vacuum cleaner to suckthe dirt or debris.

Such a cleaning robot is configured to continuously clean a cleaningarea while avoiding obstacles by changing its movement direction whenobstacles are sensed through obstacle sensors installed in the robotduring movement of the robot in the cleaning area.

However, although conventional cleaning robots can sense obstaclespresent in its running path within a certain sensible vertical range viaobstacle sensors, it cannot sense an obstacle present at a level outsidethe sensible vertical range, in particular, a level higher than thesensible vertical range. For example, where there is an obstacle presentat a level higher than the sensible vertical range of the cleaningrobot, but lower than the level of the highest portion of the cleaningrobot, the cleaning robot cannot sense this obstacle. In this case, ifthe cleaning robot runs continuously without sensing such an obstacle,the cleaning robot may become jammed between the floor and the obstacle,so that the top of the cleaning robot is pressed downwards by theobstacle. When the cleaning robot runs continuously without beingstopped in this state, the pressing force applied to the top of thecleaning robot is increased, thereby causing the body of the cleaningrobot to be damaged. Furthermore, the moving unit of the cleaning robot,in particular, the motor driving left and right wheels, may be severelydamaged. In addition, the cleaning performance of the cleaning robot isdegraded.

SUMMARY OF THE INVENTION

It is, therefore, an object of the present invention to provide aself-running robot having a pressing sensing function and a controlmethod thereof, which are capable of preventing a function degradationand damage of the self-running robot by sensing pressing on the top ofthe self-running robot, and controlling driving of the self-runningrobot based on the sensed result to allow the robot to escape from anarea where the pressing has arisen.

Another object of the invention is to provide a self-running robothaving a pressing sensing function and a control method thereof, whichare capable of preventing a function degradation and damage of theself-running robot when pressing on the robot is continued, by notifyinga user of this state in voice to take any necessary action.

The self-running robot according to an aspect of the present inventiongenerates an avoidance command in response to a sensing signal from apressure or pressing sensing unit arranged on the top thereof to escapefrom an area where the pressing has occurred. In addition, when thesensing signal is still output from the pressing sensing unit even afterthe generation of the avoidance command, the self-running robot notifiesa user of the above state to take any necessary action. To implementthis, in accordance with an aspect of the present invention, there isprovided a self-running robot having a pressing sensing function,comprising: a pressing sensing unit for sensing pressing on a top of theself-running robot; a microprocessor for controlling a driving of theself-running robot in accordance with the sensing signal from thepressing sensing unit to enable the self-running robot to escape from anarea where the pressing has occurred; a memory for storing an audiosignal used to notify the pressing; and an audio output unit forconverting the audio signal stored in the memory into an audible soundunder the control of the microprocessor and outputting the audiblesound.

The self-running robot according to another aspect of the presentinvention senses a rotational speed of left and right wheel motors tomove the self-running robot, calculates a running speed of theself-running robot, compares the calculated speed with a reference speedto determine whether pressing has arisen on the self-running robot, andoutputs an avoidance command to enable the self-running robot to escapefrom an area where the pressing has occurred when the pressing issensed. Further, when the pressing is sensed even after outputting theavoidance command, the robot notifies a user of the above state in voiceto take any necessary action.

To implement this, in accordance with another aspect of the presentinvention, there is provided a rotation detection unit for outputting asignal corresponding to a rotational speed of left and right wheelmotors to move the self-running robot; a microprocessor for controllingthe left and right wheel motors to enable the self-running robot toescape from a corresponding area when a running speed of theself-running robot computed by using the output signal from the rotationdetection unit is slower than a reference speed; a memory for storing anaudio signal used to notify the pressing; and an audio output unit forconverting the audio signal stored in the memory into an audible soundunder the control of the microprocessor and outputting the audiblesound.

The present invention as mentioned above has an advantage that it canprevent a function degradation and damage of the self-running robot bychanging a running direction of the self-running robot when pressing onthe top of the robot is sensed to allow the robot to escape from an areawhere the pressing has arisen, or notifying a user of the sensed resultin voice when the robot cannot escape from the area, to take anynecessary action.

BRIEF DESCRIPTION OF THE DRAWINGS

The above and other features and advantages of the present inventionwill become more apparent by describing in detail exemplary embodimentsthereof with reference to the attached drawings in which:

FIG. 1 is a block diagram schematically illustrating a self-runningrobot having a pressing sensing function in accordance with a preferredembodiment of the present invention;

FIG. 2 is a block diagram schematically illustrating a self-runningrobot having a pressing sensing function in accordance with anotherembodiment of the present invention;

FIG. 3 is a flowchart schematically illustrating a control procedure ofa self-running robot in accordance with a preferred embodiment of thepresent invention; and

FIG. 4 is a flowchart schematically illustrating a control procedure ofa self-running robot in accordance with another embodiment of thepresent invention.

DETAILED DESCRIPTION OF THE INVENTION

Hereinafter, exemplary embodiments according to the present inventionwill now be described in detail with reference to the accompanyingdrawings.

Further, a description will be given under the assumption that theself-running robot of the present invention is a cleaning robot that isa typical example of the self-running robot.

FIG. 1 is a block diagram illustrating a cleaning robot of aself-running robot having a pressing sensing function in accordance witha preferred embodiment of the present invention. Referring to FIG. 1,the cleaning robot having a pressing sensing function in accordance withthe present invention includes a pressing sensing unit 160 for sensingpressing on the cleaning robot, and outputting a sensing signal based onthe sensed result, a memory 170 for storing an audio signal used tonotify the pressing on the cleaning robot, an audio output unit 180 forconverting the audio signal stored in the memory 170 into an audiblesound and outputting the same, and a microprocessor 150 including arunning controller 151 for controlling driving of a driving unit 130,the microprocessor 150 controlling the overall device of the cleaningrobot, in addition to a basic construction of the cleaning robot.

The basic configuration of the cleaning robot includes a suction unit110, having a dirt sensor for sensing dirt or debris in a cleaning area,for sucking the dirt or debris sensed by the dirt sensor, a dirtreception unit 120 for receiving the dirt or debris collected by thesuction unit 110, a driving unit 130 including left and right wheelmotors 131 and 132 for moving the cleaning robot, a battery 140 forsupplying a driving power for the suction unit 110 and the driving unit130, and a microprocessor 150 for controlling the overall device of thecleaning robot. Since such a basic configuration of the cleaning robotis well known in the art, the detailed description thereof will beomitted.

The driving unit 130 controls the level of electric power supplied tothe left and right wheel motors 131 and 132 according to a controlsignal from the microprocessor 150 to move the cleaning robot. The leftand right wheel motors 131 and 132 of the driving unit 130 are connectedto the left and right wheels that are used to move the cleaning robot.Thus, the cleaning robot can run in front/back and left/right directionsaccording to rotational speeds and directions of the left and rightwheel motors 131 and 132. For example, if a control signal from therunning controller 151 represents a right-handed rotation command forthe cleaning robot, the driving unit 130 increases the level of theelectric power applied to the left wheel motor 131, rather thandecreasing the level of the electric power to the right wheel motor 132,to turn the cleaning robot right.

The pressing sensing unit 160 is arranged at, for example, the center ofthe top of the cleaning robot and may be a switch which is turned on oroff in accordance with connection or disconnection of contacts thereofdepending on a pressure applied thereto; but is not limited to the aboveexample and may be also implemented by various pressure sensors to sensea pressure. Generally, the switch of the pressing sensing unit 160 ismaintained in an OFF state while the cleaning robot moves. However, incase where a pressure is applied to the top of the cleaning robot, i.e.,pressing on the top of the cleaning robot occurs, the switch is changedto an ON state, and then a sensing signal is provided from the pressingsensing unit 160 to the microprocessor 150. The sensing signal to themicroprocessor 150 may be a current flowing via the switch. Themicroprocessor 150 determines that the pressure was applied to the topof the cleaning robot based on the sensing signal from the pressingsensing unit 160.

The memory 170 may be a nonvolatile memory in that data can be read andwritten, such as EEPROM or flash memory. An operation program and itsrelated data to drive the cleaning robot are stored in the memory 170.The data stored in the memory 170 is accessed and controlled by themicroprocessor 150. According to an aspect of the present invention, thememory 170 stores an audio signal used to notify a user of informationrepresenting that pressing on the top of the cleaning robot has beensensed. This audio signal is converted into an audible sound by theaudio output unit 180, and is then output.

The audio output unit 180 may be constituted by, for example, a voicesource reproduction chip such as a YAMAHA chip to reproduce an audiosignal stored in an audio source form in the memory 170 or a DSP chip toreproduce an audio signal stored in the memory 170 in an MP3 form. Theaudio signal stored in the memory 170 is accessed and reproduced by thecontrol of the microprocessor 150 to output via an audio output meanssuch as a speaker.

The microprocessor 150 that controls the overall device of the cleaningrobot includes a running controller 151 for controlling an operation ofthe driving unit 130 having the left and right wheel motors 131 and 132,and a pressing sensing processor 152 for outputting, when a sensingsignal is received from a pressing sensing unit 160, a control signal tothe running controller 151 to enable the cleaning robot to escape from acorresponding area according to on an avoidance algorithm and providing,when the sensing signal is continuously received from the pressingsensing unit 160 even after enabling the cleaning robot to escape fromthe corresponding area in response to the sensing signal, the audiooutput unit 180 with a control signal to notify a user of the abovestate in voice.

The running controller 151 controls the driving unit 130 to move thecleaning robot by outputting a control command depending on theoperation program of the cleaning robot. When the pressing sensingprocessor 152 receives the sensing signal from the pressing sensing unit160, it transmits a control command to the running controller 151 toenable the cleaning robot to escape from an area where the cleaningrobot is pressed according to the avoidance algorithm. The avoidancealgorithm may be a control command that causes the cleaning robot tomove backward, and rotate in a reverse direction to its previousdirection and then move again.

Meanwhile, when the sensing signal is still continuously received fromthe pressing sensing unit 160 even after enabling the cleaning robot toescape from the area where it is pressed according to the avoidancealgorithm, the pressing sensing processor 152 recognizes that thecleaning robot hasn't escaped from that area, and then outputs a controlsignal to the audio output unit 180 to notify the user of a pressingsensing audio alert message such as “pressing on the cleaning robot issensed”.

The audio output unit 180 accesses the audio signal stored in the memory170 in response to the control signal from the pressing sensingprocessor 152 and then converts the accessed audio signal into anaudible sound to output it via an audio output means such as a speakerembedded in the cleaning robot.

Accordingly, the prevent invention has an advantage in that it canprevent a function degradation and damage of the cleaning robot bychanging the moving direction of the cleaning robot to enable thecleaning robot to escape from the corresponding area according theavoidance algorithm when the pressing or pressure given on the topthereof is sensed, or notifying the user of the above state to take anynecessary action when the robot hasn't escaped from the area.

FIG. 2 is a block diagram schematically illustrating a self-runningrobot having a pressing sensing function in accordance with anotherembodiment of the present invention. As shown therein, the driving unit130 of the cleaning robot according to the present invention furthercomprises a rotation detection unit 133 for outputting a signalcorresponding to a rotational speed of the left and right wheel motors131 and 132. In this configuration, the pressing sensing processor 152computes a running speed of the cleaning robot using pulse informationprovided from the rotation detection unit 133; and outputs a controlsignal to the running controller 151 to enable the cleaning robot toescape from the corresponding area according to the avoidance algorithmwhen the computed running speed is slower than a reference speed, andprovides the audio output unit 180 with a control signal to notify theuser of the state via a voice when the computed running speed is stillslower than the reference speed even after controlling the driving ofthe cleaning robot according to the rotational speed thereof.

The rotation detection unit 133 provides a signal corresponding to therotational speed of the left and right wheel motors 131 and 132 of thedriving unit 130 to move the cleaning robot. That is, the rotationdetection unit 133 includes a left wheel detection unit 133-1 forgenerating a pulse signal representing the RPM of the left wheel motor131 and a right wheel detection unit 133-2 for generating a pulse signalrepresenting the RPM of the right wheel motor 132.

When a control signal is output from the running controller 151 of themicroprocessor 150 to the driving unit 130, the driving unit 130 drivesthe left or right wheel motor 131 or 132 in response to the controlsignal to move the cleaning robot. At this time, the left wheeldetection unit 133-1 and the right wheel detection unit 133-2 of therotation detection unit 133 generate pulse signals representing RPMs ofthe left and right wheel motors 131 and 132, respectively, and thenoutput the pulse signals to the pressing sensing processor 152.

The pressing sensing processor 152 receives the pulse signalsrepresenting respective RPMs of the left and right wheel motors 131 and132 from each of the left wheel detection unit 133-1 and the right wheeldetection unit 133-2 of the rotation detection unit 133 and thencalculates a running speed of the cleaning robot. It then compares thecalculated running speed with a reference speed of the cleaning robot tocheck whether pressing has occurred on the cleaning robot, and providesthe running controller 151 with a control signal to change the runningdirection of the cleaning robot according to the avoidance algorithmupon the occurrence of the pressing, to enable the cleaning robot toescape from the pressing.

For example, in case where a pressure or pressing force has been appliedto the top of the cleaning robot while it is moving normally, the robotwould move at a reduced speed compared to the reference speed by thepressing. Accordingly, the rotation detection unit 133 outputs a pulsesignal having a pulse period different from that of a pulse signalgenerated during the normal running.

The pressing sensing processor 152 recognizes that the pressing hasoccurred on the robot in case where a variation in the pulse period ofthe pulse signal output from the rotation detection unit 133 continuesfor a predetermined time, and outputs a control command to enable thecleaning robot to escape from the corresponding area according to theavoidance algorithm.

After controlling the cleaning robot using the avoidance algorithm, thepressing sensing processor 152 computes a running speed based on thepulse signals output from the left wheel detection unit 133-1 and theright wheel detection unit 133-2 of the rotation detection unit 133, andthen compares the computed running speed with the reference speed. Ifthe computed running speed is equal to the reference speed, the pressingsensing processor 152 recognizes the release of the pressing state andthen enables the cleaning function to be continuously executed.

In the meantime, if the computed running speed is slower than thereference speed in the comparison, the pressing sensing processor 152recognizes that the pressing state cannot be released and then outputs acontrol signal to the audio output unit 180 to notify the user of apressing sensing alert message such as “pressing on the cleaning robotis sensed” in voice.

Although there is disclosed in the above-described embodiment an examplehaving the rotation detection unit 133 and the pressing sensing unit 160separately installed, the present invention is not limited to the aboveexample but may be implemented that it has only the rotation detectionunit 133 wherein pressing on the cleaning robot is also sensed.

FIG. 3 is a flowchart schematically illustrating a control procedure ofa self-running robot in accordance with a preferred embodiment of thepresent invention. As shown, when a user inputs a driving command forthe cleaning robot at step S101, the cleaning robot performs thecleaning function according to the driving command at step S103.

When a pressure or pressing force has been applied to the top of thecleaning robot during execution of the cleaning function, the pressingsensing unit 160 provides a sensing signal to the pressing sensingprocessor 152 of the microprocessor 150. The pressing sensing processor152, when the sensing signal is continuously received from the pressingsensing unit 160 for a predetermined time at step S105, transmits acontrol command to the running controller 151 according to the avoidancealgorithm to enable the cleaning robot to escape from the correspondingarea at step 107.

In this process, the avoidance algorithm may be a control command thatallows the cleaning robot to move backward, and rotate in a reversedirection to its previous direction and then continue moving again.

The running controller 151 drives the driving unit 130 in response tothe control signal transmitted from the pressing sensing processor 152to control the cleaning robot to escape from the area.

When the sensing signal is still continuously received from the pressingsensing unit 160 even after controlling the cleaning robot according tothe avoidance algorithm at step S109, the pressing sensing processor 152recognizes that the robot hasn't escaped from the area where thepressing has occurred, and then outputs a control signal to the audiooutput unit 180 to notify the user of a pressing sensing alert messagesuch as “pressing on the robot is sensed” in voice at step S111.

That is to say, the audio output unit 180 accesses the audio signalstored in the memory 170 in response to the control signal from thepressing sensing processor 152 and then converts the accessed audiosignal into an audible sound to output the same via an audio outputmeans such as a speaker provided in the cleaning robot.

When the user inputs a driving stop command according to the pressingsensing alert message of the cleaning robot, the cleaning function ofthe cleaning robot is ended at step S113.

FIG. 4 is a flowchart schematically illustrating a control procedure ofa self-running robot in accordance with another embodiment of thepresent invention. As shown, in the present embodiment, pressing on thecleaning robot is sensed depending on the rotational speed of the leftand right wheel motors 131 and 132 of the driving unit 130 to move thecleaning robot.

Specifically, when a driving command for the cleaning robot is inputtedat step S201, the running controller 151 of the microprocessor 150outputs a control signal to the driving unit 130 to perform the cleaningfunction at step S203. Then, the driving unit 130 serves to drive theleft and right wheel motors 131 and 132 in response to the controlsignal to move the cleaning robot. During this process, the left andright wheel detection units 133-1 and 133-2 of the rotation detectionunit 133 generate pulse signals representing RPMs of the associatedmotors, and output the pulse signals to the pressing sensing processor152, respectively, at step S205.

At a next step S207, the pressing sensing processor 152 calculates arunning speed of the cleaning robot using the pulse signals,representing respective RPMs of the motors, output from the left andright wheel detection units 133-1 and 133-2 of the rotation detectionunit 133. Thereafter, it compares the calculated running speed with areference speed of the cleaning robot at step S209, and controls it tocontinue the cleaning function if the calculated running speed is equalto the reference speed.

On the other hand, if the calculated running speed is slower than thereference speed, the pressing sensing processor 152 recognizes that thepressing has occurred on the cleaning robot and then outputs a controlsignal to the running controller 151 to change the running directionaccording to the avoidance algorithm and to enable the cleaning robot toescape from the pressing at step S211.

After applying the avoidance algorithm, the pressing sensing processor152 again calculates a running speed of the cleaning robot using thepulse signals output from each of the left and right wheel detectionunits 133-1 and 133-2 of the rotation detection unit 133, and thencompares the calculated running speed with the reference speed at stepS213. If the calculated running speed is equal to the reference speed,the pressing sensing processor 152 recognizes that the pressing statehas been released and then enables the cleaning function to becontinuously executed.

Meanwhile, if the calculated running speed is slower than the referencespeed, the pressing sensing processor 152 recognizes that the pressingon the cleaning robot cannot be released using the avoidance algorithmand then outputs a control signal to the audio output unit 180 to notifythe user of a pressing sensing alert message such as “pressing on therobot is sensed” in voice at step S215.

When the user inputs a driving stop command according to the pressingsensing alert message, the cleaning function of the cleaning robot isended at step S217.

As described above, the self-running robot having a pressing sensingfunction and control method thereof in accordance with the invention canprevent a function degradation and damage of the self-running robot bysensing a pressure or pressing on the top of the self-running robot, andcontrolling driving of the self-running robot according to an avoidancealgorithm to enable the robot to escape from an area where the pressinghas arisen.

Moreover, the invention can prevent a function degradation and damage ofthe self-running robot by notifying, in case where the self-runningrobot cannot escape from an area where pressing on the robot hasoccurred using the avoidance algorithm, a user of the above state invoice to take any necessary action.

While the present invention has been described with reference toexemplary embodiments thereof, it will be understood by those skilled inthe art that various changes in form and details may be made thereinwithout departing from the scope of the present invention as defined bythe following claims.

1. A self-running robot having a pressing sensing function, comprising:a pressing sensing unit for sensing pressing on a top of theself-running robot; and a microprocessor for controlling a driving ofthe self-running robot in accordance with the sensing signal from thepressing sensing unit to enable the self-running robot to escape from anarea where the pressing has occurred.
 2. The self-running robotaccording to claim 1, wherein the microprocessor, when the pressingsensing signal is continuously received even after controlling thedriving of the self-running robot in accordance with the pressingsensing signal, notifies a user of the above state in voice.
 3. Theself-running robot according to claim 2, wherein the self-running robotcomprises: a memory for storing an audio signal used to notify thepressing; and an audio output unit for converting the audio signalstored in the memory into an audible sound under the control of themicroprocessor and outputting the audible sound.
 4. The self-runningrobot according to claim 1, wherein the pressing sensing unit is anON/OFF switch provided on the top of the self-running robot.
 5. Theself-running robot according to claim 1, further comprising a rotationdetection unit for outputting a signal corresponding to a rotationalspeed of left and right wheel motors to move the self-running robot,wherein the microprocessor controls the left and right wheel motors toenable the self-running robot to escape from a corresponding area when arunning speed of the self-running robot computed by using the outputsignal from the rotation detection unit is slower than a referencespeed.
 6. The self-running robot according to claim 5, wherein, when therunning speed of the self-running robot is slower than the referencespeed even after controlling the driving of the self-running robot inaccordance with the running speed of the self-running robot, themicroprocessor notifies a user of the above state in voice.
 7. Theself-running robot according to claim 6, wherein the self-running robotcomprises: a memory for storing an audio signal used to notify thepressing; and an audio output unit for converting the audio signalstored in the memory into an audible sound under the control of themicroprocessor and outputting the audible sound.
 8. The self-runningrobot according to claim 1, wherein the self-running robot is a cleaningrobot.
 9. A self-running robot having a pressing sensing function,comprising: a rotation detection unit for outputting a signalcorresponding to a rotational speed of left and right wheel motors tomove the self-running robot; and a microprocessor for controlling theleft and right wheel motors to enable the self-running robot to escapefrom a corresponding area when a running speed of the self-running robotcomputed by using the output signal from the rotation detection unit isslower than a reference speed.
 10. The self-running robot according toclaim 9, wherein, when the running speed of the self-running robot isslower than the reference speed even after controlling the driving ofthe self-running robot in accordance with the running speed of theself-running robot, the microprocessor notifies a user of the abovestate in voice.
 11. The self-running robot according to claim 10,wherein the self-running robot comprises: a memory for storing an audiosignal used to notify the pressing; and an audio output unit forconverting the audio signal stored in the memory into an audible soundunder the control of the microprocessor and outputting the audiblesound.
 12. The self-running robot according to claim 9, wherein theself-running robot is a cleaning robot.
 13. A method for controlling aself-running robot, comprising the steps of: receiving a sensing signalfrom a pressing sensing unit to sense pressing on a top of theself-running robot; and controlling a driving of the self-running robotin accordance with the sensing signal to enable the self-running robotto escape from an area where the pressing has occurred.
 14. The methodaccording to claim 13, further comprising the step of notifying, whenthe pressing sensing signal is continuously received even aftercontrolling the driving of the self-running robot in accordance with thepressing sensing signal, a user of the above state in voice.
 15. Themethod according to claim 13, further comprising the steps: receiving asignal corresponding to a rotational speed of left and right wheelmotors to move the self-running robot from a rotation detection unit;and controlling the left and right wheel motors to enable theself-running robot to escape from a corresponding area when a runningspeed of the self-running robot computed by using the output signal fromsaid step is slower than a reference speed.
 16. The method according toclaim 15, further comprising the step of notifying, when the runningspeed of the self-running robot is slower than the reference speed evenafter controlling the driving of the self-running robot in accordancewith the running speed of the self-running robot, a user of the abovestate in voice.
 17. The method according to claim 13, wherein theself-running robot is a cleaning robot.
 18. A method for controlling aself-running robot, comprising the steps of: receiving a signalcorresponding to a rotational speed of left and right wheel motors tomove the self-running robot from a rotation detection unit; andcontrolling the left and right wheel motors to enable the self-runningrobot to escape from a corresponding area when a running speed of theself-running robot computed by using the output signal from said step isslower than a reference speed.
 19. The method according to claim 18,further comprising the step of notifying, when the running speed of theself-running robot is slower than the reference speed even aftercontrolling the driving of the self-running robot in accordance with therunning speed of the self-running robot, a user of the above state invoice.
 20. The method according to claim 18, wherein the self-runningrobot is a cleaning robot.